<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>生命周期</title>
</head>
<body>
    <div id="test"></div>
    <script src="./js/react.development.js" crossorigin></script> 
    <script src="./js/react-dom.development.js" crossorigin></script>
    <script src="./js/babel.min.js"></script>
    <script type="text/babel"> /* 此处一定要写babel */
        // 创建组件
        class Life extends React.Component{
            state = {opacity: 1}
            death = () => {
                // 卸载组件
                clearInterval(this.timer)
                ReactDOM.unmountComponentAtNode(document.getElementById('test'))
                
            }
            action = () => {
                this.timer = setInterval(() => {
                    let { opacity } = this.state
                    opacity -= 0.1
                    if(opacity <= 0) opacity = 1
                    // 设置新的透明度
                    this.setState({opacity})
                },200)
            }
            // 组件挂在完毕调用
            componentDidMount(){
                this.action()
            }

            render() {
                /**
                 * render调用的时机: 初始化渲染、状态更新之后
                 * */
                return (
                    <div>
                        <h2 style={{opacity: this.state.opacity}}>React学不会怎么办？</h2>
                        <button onClick={this.death}>不活了</button>
                    </div>
                )
            }
        }

        ReactDOM.render(<Life />, document.getElementById('test'))
    </script>
</body>
</html>